We will continue to study the molecular mechanisms involved in the erasure process of Dictyostelium discoideum, a dedifferentiation involving the programmed loss of chemotactic functions. In particular, we will examine the target for cAMP inhibition of erasure and the membrane changes associated with the erasure event. Changes in gene expression will be examined both in vivo and in vitro, employing a rabbit reticulocyte system for protein synthesis. We will also continue to develop and apply methods for examining the complexity and relationships of developmental timers. The methods will be applied to Dictyostelium morphogenesis, yeast budding, and water mold sporulation. Analysis of timer mutants will continue.